Alert archive / Maryland / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 460, NWS Baltimore/Washington

August 27, 2021Montgomery County, Maryland

NWS Baltimore/Washington issued this severe thunderstorm warning at Aug 27, 2021, 2:35 PM EDT for Montgomery County, Maryland. It was in force for 40 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 27, 2021, 2:35 PM EDT (18:35 UTC)
Expired
Aug 27, 2021, 3:15 PM EDT
In force
40 min
Issued by
NWS Baltimore/Washington
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Montgomery County, MD

The radar

The Sterling radar (KLWX), 29 km from the middle of the area, began a volume at 18:39 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Aug 27, 3:11 PM EDTTSTM WND GST 622 E North Potomac, MD
Aug 27, 3:16 PM EDTTSTM WND GST 621 Nw Gaithersburg, MD
Aug 27, 3:21 PM EDTTSTM WND DMG2 S Rockville, MDMULTIPLE TREES DOWN IN THE WILLERBURN ACRES NEIGHBORHOOD.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 36 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 6.6 hours before the alert went out and 25 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2021-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 780 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Washington/Dulle, VA at 12:00Z on 2021-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
780 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
983 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
41 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

186 
WUUS51 KLWX 271835
SVRLWX
MDC031-271915-
/O.NEW.KLWX.SV.W.0460.210827T1835Z-210827T1915Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Baltimore MD/Washington DC
235 PM EDT Fri Aug 27 2021

The National Weather Service in Sterling Virginia has issued a

* Severe Thunderstorm Warning for...
  Central Montgomery County in central Maryland...

* Until 315 PM EDT.

* At 234 PM EDT, a severe thunderstorm was located near Lowes Island,
  moving east at 15 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damaging winds will cause some trees and large branches 
           to fall. This could injure those outdoors, as well as 
           damage homes and vehicles. Roadways may become blocked by 
           downed trees. Localized power outages are possible. 
           Unsecured light objects may become projectiles.

* Locations impacted include...
  Germantown, Rockville, Gaithersburg, Olney, Damascus, Lowes Island,
  Poolesville, Aspen Hill, Potomac, North Bethesda, Montgomery
  Village, North Potomac, Redland, Great Falls, Boyds, Rossmoor,
  Wheaton-Glenmont, Wheaton, Cloverly and Clarksburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3926 7709 3924 7704 3911 7696 3900 7725
      3903 7725 3903 7727 3905 7730 3906 7734
      3907 7740 3914 7745 3927 7713
TIME...MOT...LOC 1834Z 250DEG 12KT 3909 7732 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

LFR
2 follow-up statements
361 
WWUS51 KLWX 271856
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
256 PM EDT Fri Aug 27 2021

MDC031-271915-
/O.CON.KLWX.SV.W.0460.000000T0000Z-210827T1915Z/
Montgomery MD-
256 PM EDT Fri Aug 27 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 PM EDT
FOR CENTRAL MONTGOMERY COUNTY...

At 255 PM EDT, a severe thunderstorm was located over North Potomac,
or near Gaithersburg, moving east at 5 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damaging winds will cause some trees and large branches to 
         fall. This could injure those outdoors, as well as damage 
         homes and vehicles. Roadways may become blocked by downed 
         trees. Localized power outages are possible. Unsecured 
         light objects may become projectiles.

Locations impacted include...
Germantown, Rockville, Gaithersburg, Olney, Damascus, Lowes Island,
Aspen Hill, Potomac, North Bethesda, Montgomery Village, North
Potomac, Redland, Great Falls, Boyds, Rossmoor, Wheaton-Glenmont,
Wheaton, Cloverly, Clarksburg and Glenmont.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3926 7709 3924 7704 3911 7696 3900 7725
      3903 7725 3903 7727 3905 7730 3906 7734
      3910 7735 3917 7738 3927 7713
TIME...MOT...LOC 1855Z 263DEG 7KT 3909 7728 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

LFR
577 
WWUS51 KLWX 271907
SVSLWX

Severe Weather Statement
National Weather Service Baltimore MD/Washington DC
307 PM EDT Fri Aug 27 2021

MDC031-271916-
/O.EXP.KLWX.SV.W.0460.000000T0000Z-210827T1915Z/
Montgomery MD-
307 PM EDT Fri Aug 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL MONTGOMERY COUNTY WILL
EXPIRE AT 315 PM EDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

Remember, a Severe Thunderstorm Warning still remains in effect for
portions of Central Montgomery County.

LAT...LON 3926 7709 3924 7704 3911 7696 3900 7725
      3903 7725 3903 7727 3905 7730 3906 7734
      3910 7735 3917 7738 3927 7713
TIME...MOT...LOC 1906Z 250DEG 12KT 3910 7725 

$$

LFR

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Baltimore/Washington wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 27, 10:40 AM EDT, 3 hours 55 minutes earlier.

Area forecast discussion, Aug 27, 10:40 AM EDT, 3 hours 55 minutes before
Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
1040 AM EDT Fri Aug 27 2021

.SYNOPSIS...
A weak cold front will approach the region this afternoon
before moving into the area tonight into Saturday. The boundary
will stall out over our area through early next week. Another
boundary may impact our region midway through next week. A
tropical influence of moisture from a tropical system moving
into the Gulf of Mexico this week could enhance showers and
thunderstorms during the middle to later part of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
A light south to southwest flow through the low-levels will
continue around the high over the Atlantic and ahead of the
approaching cold front, and this will cause more hot and humid
conditions this afternoon with max temps in the lower to middle
90s for most areas with heat indices in the upper 90s to lower
100s. Confidence is too low for a heat advisory since dewpoints
may mix down just a bit around peak heating, and there will be
more showers and thunderstorms during peak heating as well.

A potent shortwave will slowly move east, passing through our
area this afternoon and evening. At the same time, a pressure
trough will be over our area, and it may be enhanced somewhat by
the shortwave. A light flow that means more boundaries from
terrain circulation and the Bay/Potomac breezes are expected as
well.

Strong to extreme instability is expected this afternoon and
evening with 1000-2000 J/kg MLCAPE already present near and east
of the Blue Ridge as of 12z per mesoanalysis. Mid-level lapse
rates are modest 6 C/km in the 12z RAOB IAD as is to be expected
in a moist late summer environment and may actually decrease
somewhat through midday before steepening slightly again late
this afternoon. Even so, dew points near or in excess of 70
degrees and PWs exceeding 2 inches should result in ample MLCAPE
of 2500-3500 J/kg east of I-81. A weak shortwave perturbation
over eastern WV this morning will drift eastward through the
day, resulting in a sharpening lee pressure trough which should
ignite numerous thunderstorms this afternoon. Despite weak flow
of 15 kts in the mid-levels, the combination of strong
convergence along the lee trough couple with added convergence,
lift and modest low level directional shear across bay/river
breeze circulations should be enough to loosely organize cells
into clusters capable of producing scattered wind damage; a
couple of considerable microbursts can't be completely ruled out
give a slight enhancement of about 20 kts at 700 mb around the
northern periphery of ridging off the Carolinas and DCAPE
around 1000 J/kg. Large hail cannot be ruled out either given
the strong to extreme instability. In addition, the abundant
CAPE in the hail growth zone with deep moist profiles may result
in prolific lightning producing storms this afternoon and
evening. HREF probabilities of updrafts speeds >20 m/s of
50-70% support the notion of scattered severe thunderstorm
coverage this afternoon and evening.

A Flash Flood Watch is in effect for northeastern MD as well as
the Baltimore and Washington Metro areas. Thunderstorms are most
likely across these areas, and this overlays where the best
moisture is. Also, as the shortwave passes through, it does
appear that it will be strong enough for low pressure to
develop. Most guidance closes off an 850mb low over northeastern
MD. This will enhance forcing late this afternoon through this
evening, causing a better chance for training convection across
the Baltimore metro area into northeastern MD. Farther
southwest, convection may be a little more progressive across
the DC area, but there may be a couple rounds, and very heavy
rainfall rates may still cause issues with flash flooding in
urban areas even if it is somewhat progressive. That's why the
watch was issued for this area. An expansion of the watch may be
needed in area to the northwest into north-central MD, or even
across portions of southern MD. Will continue to monitor this
possibility throughout the day. While the best chance for
numerous thunderstorms will be late this afternoon and evening,
an earlier initiation is possible along the Bay/Potomac breezes
since there may be a little more convergence (southeast wind
into south or southwest wind). That's why the watch starts
earlier this afternoon.

The shortwave will move off to the east later this evening and
overnight. Convection should dissipate this evening for most
areas, but it may hang around for a bit across northeastern MD
before dissipating overnight. Areas of fog and low clouds are
possible overnight.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
High pressure will build to our north and east Saturday behind a
shortwave, and this will cause a weak cold front to advance
farther southwest, most likely stalling out near the Potomac
River. More showers and thunderstorms are possible Saturday
across anywhere, but the best chance for stronger to perhaps
even severe storms as well as an isolated flash flood threat
will be near and southwest of the boundary (most likely
southwest of the Potomac River into the Potomac Highlands and
central VA).

Convection will likely dissipate later Saturday night, but more
low clouds and fog area possible Fog may be locally dense as
well.

The boundary will remain nearly stationary for Sunday, but it
should weaken as upper-level high builds closer. Therefore, it
will likely turn out warm and humid. More showers and
thunderstorms are possible, with the best chance for a stronger
storm being south and west of the Potomac River. Coverage may be
more isolated or widely scattered since there will be height
rises from the building upper-level high.

More warm and humid conditions are expected Sunday night as
convection wanes, and there may be areas of low clouds and fog.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
The upper-level ridge will continue to break down early in the week,
with a trough moving east out of the midwest towards the area.
Meanwhile the aforementioned stalled frontal boundary will remain
nearby. This, paired with some pieces of upper-level energy swinging
through, will lead to daily chances for showers and storms. Will
remain hot and humid Monday with highs in the low 90s before cooling
off into the mid to upper 80s Tuesday afternoon as the ridge breaks
down.

The real concern into next week will be what the remnants of what is
now Tropical Storm Ida will bring towards the region. Current
forecast has Ida making landfall along the Gulf coast and then
tracking up towards the region. With the approaching upper trough
out of the midwest and the stalled surface front still lingering
around, this could lead to some flooding concerns towards the middle
of the week. At this time, the placement of all of the features at
play is far to uncertain to pin down exactly where the heaviest
rainfall occurs, but it will at least be nearby if not over our
region. Now, should Ida end up tracking to our west, then we run the
risk for severe weather as well. However, at this time that appears
to be the least likely solution. Will have to monitor this situation
closely in the coming days and see what becomes of Ida and what
level of impact we may see across the Mid-Atlantic.

See hurricanes.gov for the latest forecast information on Tropical
Storm Ida.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
Thunderstorms are likely, especially late this afternoon into
this evening. However, convection may fire up earlier this
afternoon along the Bay/Potomac breezes near KDCA, KBWI, and
KMTN. Any thunderstorms that develop may produce gusty winds and
subVFR cigs/vsbys.

Convection will wane overnight, but patchy fog is possible
toward morning. Fog may be a little more widespread compared to
recent days due to more rainfall expected this
afternoon/evening. IFR vsbys are possible. Low clouds may impact
the northeastern terminals Saturday morning, especially KBWI,
KMTN and possibly KDCA and KIAD. MVFR cigs are most likely.

More showers and thunderstorms are possible Saturday
afternoon/evening as well as Sunday afternoon/evening. The best
chance for a stronger storm will be across KMRB and KCHO. Areas
of low clouds and fog are likely Saturday night into Sunday
morning, and possible Sunday night.

A stalled frontal boundary will lead to a chance for showers and
thunderstorms on Monday and Tuesday across the region, which
could lead to some flight restrictions at times.

&&

.MARINE...
A weak cold front will approach through tonight before passing
through Saturday. Light southerly or onshore winds through this
evening will likely turn to the north and northeast later
tonight through Saturday. Winds should remain below SCA
criteria, but gusts may be close for a period later Saturday
into Saturday night due to a weak pressure surge.

Light onshore winds are expected Sunday through Sunday night.

Thunderstorms are likely over the water this afternoon and
evening, and some may cause gusty to damaging wind gusts. More
thunderstorms are possible Saturday afternoon and evening, and
again Sunday afternoon and evening, but coverage may be more
isolated or scattered.

While subSCA winds are expected Monday and Tuesday, there are
thunderstorms in the forecast each day. Gusty winds are possible
in these storms and could lead to some SMWs or MWSs.

&&

.TIDES/COASTAL FLOODING...
A light southerly or onshore flow may increase as it turns north
and northeast Saturday into Saturday night, before turning light
again but remaining onshore Sunday. This will cause elevated
water levels. Confidence for minor flooding is low at this time
since the flow will be light, but it may be close for sensitive
areas.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...Flash Flood Watch through this evening for DCZ001.
MD...Flash Flood Watch through late tonight for MDZ006-008-011-014-
     507-508.
     Flash Flood Watch through this evening for MDZ013-504-506.
VA...Flash Flood Watch through this evening for VAZ053-054.
WV...None.
MARINE...Flash Flood Watch through this evening for ANZ535.

&&

SYNOPSIS...BJL
NEAR TERM...BJL/KLW/DHOF
SHORT TERM...BJL
LONG TERM...CJL
AVIATION...KLW/CJL
MARINE...KLW/CJL
TIDES/COASTAL FLOODING...BJL
Hazardous weather outlook, Aug 27, 5:45 AM EDT, 8 hours 50 minutes before
Hazardous Weather Outlook
National Weather Service Baltimore MD/Washington DC
545 AM EDT Fri Aug 27 2021

ANZ530>543-DCZ001-MDZ008-011-013-014-016>018-504-506-508-
VAZ052>057-281000-
Chesapeake Bay north of Pooles Island MD-
Chesapeake Bay from Pooles Island to Sandy Point MD-
Chesapeake Bay from Sandy Point to North Beach MD-
Chesapeake Bay from North Beach to Drum Point MD-
Chesapeake Bay from Drum Point MD to Smith Point VA-
Tidal Potomac from Key Bridge to Indian Head MD-
Tidal Potomac from Indian Head to Cobb Island MD-
Tidal Potomac from Cobb Island MD to Smith Point VA-
Patapsco River including Baltimore Harbor-
Chester River to Queenstown MD-Eastern Bay-
Choptank River to Cambridge MD and the Little Choptank River-
Patuxent River to Broomes Island MD-
Tangier Sound and the inland waters surrounding Bloodsworth
Island-District of Columbia-Cecil-Southern Baltimore-
Prince Georges-Anne Arundel-Charles-St. Marys-Calvert-
Central and Southeast Montgomery-Central and Southeast Howard-
Southeast Harford-Prince William/Manassas/Manassas Park-Fairfax-
Arlington/Falls Church/Alexandria-Stafford-Spotsylvania-
King George-
545 AM EDT Fri Aug 27 2021

This Hazardous Weather Outlook is for the Maryland portion of the
Chesapeake Bay, Tidal Potomac River, and I-95 corridor through
central Maryland, northern Virginia, and District of Columbia.

.DAY ONE...Today and Tonight

Severe storms are possible this afternoon and evening, with
damaging winds being the primary threat.

A Flash Flood Watch is in effect for the Baltimore and Washington
Metropolitan areas as well as northeastern Maryland for this
afternoon into tonight. Scattered instances of flash flooding are
possible due to heavy rain from thunderstorms. Elsewhere, isolated
instances of flash flooding are possible.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Isolated severe thunderstorms are possible during the afternoon
and evening hours Saturday and Sunday, and again for Tuesday.
Scattered severe storms are possible Monday.

Isolated instances of flash flooding are possible Saturday through
Tuesday, and scattered instances of flash flooding are possible
Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and evening.

MDZ003>006-503-505-507-VAZ025>031-036>040-050-051-501-502-505>508-
WVZ050>053-055-281000-
Washington-Frederick MD-Carroll-Northern Baltimore-
Northwest Montgomery-Northwest Howard-Northwest Harford-Augusta-
Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-Nelson-
Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper-
Northern Fauquier-Southern Fauquier-Western Loudoun-
Eastern Loudoun-Northern Virginia Blue Ridge-
Central Virginia Blue Ridge-Hampshire-Morgan-Berkeley-Jefferson-
Hardy-
545 AM EDT Fri Aug 27 2021

This Hazardous Weather Outlook is for portions of eastern West
Virginia, northern and central Virginia, and central and western
Maryland.

.DAY ONE...Today and Tonight

Severe storms are possible this afternoon and evening, with
damaging winds being the primary threat. The best chance for
severe storms will be near and east of the Interstate 81 corridor
across eastern West Virginia, northern Virginia, and into central
Maryland.

A Flash Flood Watch is in effect for portions of central Maryland
near Washington and Baltimore. Scattered instances of flash
flooding are possible due to heavy rain from thunderstorms.
Elsewhere, isolated instances of flash flooding are possible.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Isolated severe thunderstorms are possible during the afternoon
and evening hours Saturday and Sunday, and again for Tuesday.
Scattered severe storms are possible Monday.

Isolated instances of flash flooding are possible Saturday through
Tuesday, and scattered instances of flash flooding are possible
Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and evening.

MDZ001-501-502-VAZ503-504-WVZ501>506-281000-
Garrett-Extreme Western Allegany-Central and Eastern Allegany-
Western Highland-Eastern Highland-Western Grant-Eastern Grant-
Western Mineral-Eastern Mineral-Western Pendleton-
Eastern Pendleton-
545 AM EDT Fri Aug 27 2021

This Hazardous Weather Outlook is for the Allegheny Front
counties in western Maryland, eastern West Virginia, and Highland
County Virginia.

.DAY ONE...Today and Tonight

Isolated instances of flash flooding and severe storms are
possible this afternoon and evening.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Isolated severe thunderstorms are possible during the afternoon
and evening hours Saturday and Sunday, and again for Tuesday.
Scattered severe storms are possible Monday.

Isolated instances of flash flooding are possible Saturday through
Tuesday, and scattered instances of flash flooding are possible
Wednesday.

.SPOTTER INFORMATION STATEMENT...

Limited spotter activation may be needed this afternoon and
evening.

In the hours before

Local storm report, Aug 27, 11:11 AM EDT, 3 hours 24 minutes before
PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1111 AM EDT FRI AUG 27 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0135 PM     MARINE TSTM WIND QUANTICO MARINE CORP    38.51N  77.30W
08/26/2021  E39 MPH          PRINCE WILLIAM     VA   AWOS

0143 PM     TSTM WND DMG     1 WSW TRIANGLE          38.54N  77.34W
08/26/2021                   PRINCE WILLIAM     VA   EMERGENCY MNGR

            TREE DOWN ON ROUTE 1 NEAR THE INTERSECTION WITH JOPLIN
            ROAD

0148 PM     TSTM WND DMG     3 ENE GARRISONVILLE     38.51N  77.37W
08/26/2021                   STAFFORD           VA   DEPT OF HIGHWAYS

            TREE DOWN ON NORTHBOUND US-1 JEFFERSON DAVIS HIGHWAY
            NEAR VA-637 TELEGRAPH ROAD.

0150 PM     TSTM WND DMG     1 W WIDEWATER           38.46N  77.34W
08/26/2021                   STAFFORD           VA   911 CALL CENTER

            TREE DOWN ON POWER LINES IN THE 100 BLOCK OF VA-635
            DECATUR ROAD.

0230 PM     TSTM WND DMG     2 SW STAFFORD           38.40N  77.43W
08/26/2021                   STAFFORD           VA   911 CALL CENTER

            TREES DOWN NEAR THE INTERSECTION OF US-1 JEFFERSON
            DAVIS HIGHWAY AND SHADY HILL LANE.

0240 PM     TSTM WND DMG     3 NW LEELAND            38.38N  77.47W
08/26/2021                   STAFFORD           VA   911 CALL CENTER

            TREE DOWN IN THE 100 BLOCK OF PINE VIEW DRIVE.

0240 PM     TSTM WND DMG     4 SE STAFFORD           38.38N  77.36W
08/26/2021                   STAFFORD           VA   911 CALL CENTER

            TREES DOWN IN THE 2100 BLOCK OF VA-608 BROOKE ROAD, AND
            NEAR THE INTERSECTION OF VA-608 BROOKE ROAD AND VA-628
            ESKIMO HILL ROAD.

0240 PM     TSTM WND DMG     1 NE FALMOUTH           38.34N  77.45W
08/26/2021                   STAFFORD           VA   DEPT OF HIGHWAYS

            TREE DOWN ON NORTHBOUND VA-627 FORBES STREET NEAR
            THOMAS JEFFERSON PLACE.

0240 PM     TSTM WND DMG     3 WNW LOWER MARLBORO    38.68N  76.72W
08/26/2021                   PRINCE GEORGES     MD   DEPT OF HIGHWAYS

            TREE DOWN ON NORTHBOUND MD-382 CROOM ROAD AT RIVER
            AIRPORT ROAD.

0334 PM     TSTM WND DMG     1 W ALEXANDRIA          38.82N  77.10W
08/26/2021                   CITY OF ALEXANDRIA VA   EMERGENCY MNGR

            TREE DOWN ON THE 1900 BLOCK OF SOUTH HOWARD STREET

0335 PM     FLOOD            1 NE FALMOUTH           38.35N  77.45W
08/26/2021                   STAFFORD           VA   DEPT OF HIGHWAYS

            VA-627 FORBES STREET BLOCKED DUE TO STANDING WATER.

0343 PM     HAIL             1 SW ROSSLYN            38.89N  77.08W
08/26/2021  M0.75 INCH       ARLINGTON          VA   BROADCAST MEDIA

0343 PM     TSTM WND DMG     BARCROFT                38.86N  77.10W
08/26/2021                   ARLINGTON          VA   EMERGENCY MNGR

            MULTIPLE TREES DOWN NEAR THE INTERSECTION OF 14TH
            STREET AND SOUTH POLLARD STREET

0357 PM     TSTM WND DMG     2 ESE KLINE GAP         39.07N  79.16W
08/26/2021                   GRANT              WV   TRAINED SPOTTER

            TREE DOWN ON HOUSE ON THE 100 BLOCK OF BEAGLE BOOT LANE

0357 PM     TSTM WND DMG     1 NE NATIONAL ZOO       38.94N  77.04W
08/26/2021                   DISTRICT OF COLUMB DC   BROADCAST MEDIA

            LARGE TREES DOWN WITH AT LEAST ONE SNAPPED ON 16TH
            STREET NORTHWEST NEAR PINEY BRANCH.

0358 PM     TSTM WND DMG     1 SE MAYSVILLE          39.10N  79.15W
08/26/2021                   GRANT              WV   EMERGENCY MNGR

            2 TREES DOWN ALONG LUNICE CREEK HIGHWAY JUST SE OF
            MAYSVILLE.

0400 PM     TSTM WND DMG     2 NW CATHOLIC UNIVERSIT 38.96N  77.03W
08/26/2021                   DISTRICT OF COLUMB DC   BROADCAST MEDIA

            TREES DOWN ON NORTHBOUND US-29 GEORGIA AVENUE NORTHWEST
            NEAR JEFFERSON STREET NORTHWEST.

0405 PM     TSTM WND DMG     1 E CHERRYDALE          38.90N  77.09W
08/26/2021                   ARLINGTON          VA   DEPT OF HIGHWAYS

            TREES DOWN ON I-66 CUSTIS MEMORIAL PARKWAY NEAR MILE
            MARKER 73.

0405 PM     TSTM WND DMG     1 ENE CHERRYDALE        38.90N  77.10W
08/26/2021                   ARLINGTON          VA   911 CALL CENTER

            TWO TO THREE DOZEN REPORTS OF TREES AND WIRES DOWN IN
            ARLINGTON.

0405 PM     TSTM WND DMG     1 NE AMERICAN UNIVERSIT 38.95N  77.07W
08/26/2021                   DISTRICT OF COLUMB DC   911 CALL CENTER

            THERE WERE ABOUT TWO DOZEN REPORTS OF TREES AND WIRES
            BLOWN DOWN, MAINLY ACROSS NORTHWEST DC.

0410 PM     TSTM WND DMG     1 ENE HYATTSVILLE       38.96N  76.94W
08/26/2021                   PRINCE GEORGES     MD   DEPT OF HIGHWAYS

            TREE AND WIRES DOWN NEAR THE INTERSECTION OF US-1
            BALTIMORE AVENUE AND MD-410 EAST-WEST HIGHWAY.

0412 PM     TSTM WND DMG     1 WNW AMERICAN UNIVERSI 38.94N  77.10W
08/26/2021                   DISTRICT OF COLUMB DC   FIRE DEPT/RESCUE

            TREE ON A HOUSE IN THE 4100 BLOCK OF FORDHAM ROAD
            NORTHWEST.

0415 PM     FLOOD            2 ESE ARLINGTON         38.87N  77.07W
08/26/2021                   ARLINGTON          VA   911 CALL CENTER

            HIGH STANDING WATER PARTIALLY BLOCKING VA-244 COLUMBIA
            PIKE NEAR VA-27 SOUTH WASHINGTON BOULEVARD.

0417 PM     TSTM WND DMG     1 WNW LITTLE FALLS      38.94N  77.13W
08/26/2021                   FAIRFAX            VA   BROADCAST MEDIA

            TREES DOWN ON SOUTHBOUND GEORGE WASHINGTON PARKWAY AT
            VA-123 DOLLEY MADISON BOULEVARD/CHAIN BRIDGE ROAD.

0426 PM     TSTM WND DMG     1 ENE THE AMERICAN LEGI 38.97N  77.17W
08/26/2021                   MONTGOMERY         MD   BROADCAST MEDIA

            TREES DOWN ON WESTBOUND MACARTHUR BOULEVARD NEAR
            PERSIMMON TREE ROAD.

0457 PM     FLOOD            4 NE STONES CORNER      38.38N  77.34W
08/26/2021                   STAFFORD           VA   911 CALL CENTER

            VA-623 HARRELL ROAD AND VA-608 BROOKE ROAD BLOCKED BY
            HIGH WATER AT CRESTWOOD LANE.

0515 PM     TSTM WND DMG     KEYSER                  39.44N  78.98W
08/26/2021                   MINERAL            WV   911 CALL CENTER

            TWO TREES DOWN IN KEYSER, INCLUDING ONE ONTO A HOUSE.

0527 PM     FLOOD            1 ENE RIVERCREST        38.92N  77.11W
08/26/2021                   DISTRICT OF COLUMB DC   BROADCAST MEDIA

            CANAL ROAD NORTHWEST PARTIALLY BLOCKED BY HIGH WATER
            NEAR ARIZONA AVENUE NORTHWEST.

0530 PM     TSTM WND DMG     3 SSW RIO               39.09N  78.70W
08/26/2021                   HARDY              WV   911 CALL CENTER

            TREE DOWN ALONG WV-29 SPERRYS RUNS ROAD.

0532 PM     TSTM WND DMG     2 NW LONG GREEN         39.49N  76.54W
08/26/2021                   BALTIMORE          MD   TRAINED SPOTTER

            TREE DOWN AND LARGE BRANCHES DOWN ON BLENHEIM ROAD
            NORTH.

0610 PM     TSTM WND DMG     FLINTSTONE              39.70N  78.57W
08/26/2021                   ALLEGANY           MD   911 CALL CENTER

            NUMEROUS TREES DOWN IN THE FLINTSTONE AREA.

&&

EVENT NUMBER LWX2105606 LWX2105608 LWX2105607 LWX2105609 LWX2105610
LWX2105626 LWX2105627 LWX2105629 LWX2105632 LWX2105617 LWX2105611
LWX2105612 LWX2105615 LWX2105613 LWX2105620 LWX2105614 LWX2105624
LWX2105616 LWX2105622 LWX2105625 LWX2105618 LWX2105623 LWX2105621
LWX2105619 LWX2105631 LWX2105628 LWX2105635 LWX2105630 LWX2105636
LWX2105633 LWX2105634

DH

The office that day

Everything else NWS Baltimore/Washington issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 27, 2:56 AM EDTFlash Flood WatchLWXAnne Arundel, Baltimore, Cecil, Harford, Howard, Montgomery and 2 more17 hr
Aug 27, 3:05 PM EDTSevere Thunderstorm WarningLWXMontgomery40 min
Aug 27, 3:25 PM EDTSevere Thunderstorm WarningLWXFrederick30 min
Aug 27, 3:36 PM EDTSevere Thunderstorm Warning Considerable damage threatLWXMontgomery, Prince George's19 min
Aug 27, 4:11 PM EDTAreal Flood WarningLWXMontgomery, Prince George's3 hr
Aug 27, 4:14 PM EDTSevere Thunderstorm WarningLWXCarroll, Frederick46 min
Aug 27, 4:44 PM EDTAreal Flood WarningLWXPrince George's3 hr
Aug 27, 4:59 PM EDTSevere Thunderstorm WarningLWXAnne Arundel33 min
Aug 27, 5:06 PM EDTSevere Thunderstorm WarningLWXBaltimore, Carroll20 min
Aug 27, 5:21 PM EDTSevere Thunderstorm WarningLWXCharles, Prince George's39 min
Aug 27, 5:52 PM EDTSevere Thunderstorm WarningLWXBaltimore, Harford53 min
Aug 27, 6:10 PM EDTSevere Thunderstorm WarningLWXCharles32 min
Aug 27, 6:11 PM EDTAreal Flood WarningLWXCharles, Prince George's3 hr
Aug 27, 6:13 PM EDTAreal Flood WarningLWXBaltimore, Harford3 hr
Aug 27, 6:17 PM EDTSevere Thunderstorm WarningLWXBaltimore, Harford29 min
Aug 27, 6:28 PM EDTSevere Thunderstorm WarningLWXCalvert, Charles, Prince George's, Saint Mary's47 min

Nearby

Severe Thunderstorm Warnings in Maryland, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.